Hydrodynamics of three-dimensional density currents

Density current is a dense fluid, which is continuously released from a source of rectangular cross section and spreads down a sloping surface inside a lighter, motionless fluid. A CFD code has been developed to describe salt solution density current, which propagates threedimensionally in deep ambient water. The equations of continuity, momentum conservation, and diffusion are solved simultaneously in the fixed Cartesian directions, on a non-staggered grid using finite volume scheme.The velocity–pressure coupling is handled by SIMPLEC model. Comparison of the computed width of the density currents at the different bed slopes and inlet buoyancy fluxes, with the experimental data, shows a good agreement between them. The center-plate velocity profiles are compared with experiment. Results showthe three-dimensional dense layer approaches a normal state shortly after release and the flow behaves as two-dimensional. At low bed slope, lateral propagation increases with concentration and decreases the 3-D length.This solving provides a physical understanding of such complex phenomena.